Tables 6 and 7 list detailed results for the 30 most significant SNPs from the meta-analysis of AD and ND, respectively. None of the SNPs reached genome-wide significance in the meta-analysis. To explore whether the marginally significant results contain SNPs from genes that form biological meaningful networks we constructed a connectivity diagram based on information in the Ingenuity database. The gene-products (N=308) were manually grouped based on the related structure or function of their encoded proteins. Figure 1 shows a group of 15 ion-channels, of which 6 contained one or more SNPs with a p-value smaller than 0.0001 in the meta-analyses, including the potassium voltage-gated channels KCNMA1 on chromosome 10 (p=8.91×10−6, rs592676) and KCNC2 on chromosome 12 (p=2.1×10−5, rs17803126) for ND. The Figure also shows a group of cell adhesion molecules. The most significant results are found for PCDH15 on chromosome 15 (p=1.58×10−5, rs1935468) and GPC5 (p=5.26×10−5, rs716623) on chromosome 13, both associated with AD. Other interesting results in this group are DSCAM on chromosome 21 (p=4.99×10−4, rs2837524) and CNTNAP2 (p=1.11×10−4, rs2707592), which are both associated with ND. CNTNAP2 is also ranked second for AD in the NTR sample (p=2.61×10−6, rs851712).
